Advanced Assembly Programming - The HCS12/9S12: An Introduction to Software and Hardware Interfacing - page 203

cmdlinelen equ 40

org $1000

inbuf ds.b 20

err_flag ds.b 1

sign_flag ds.b 1

org $1500

lds #$1500

ldd #prompt1

jsr [printf,PCR] ; output a prompt to remind the user to enter

ldd #cmdlinelen ; an integer

pshd

ldd #inbuf

call [getcmdline,PCR] ; read in a string that represents an integer

leas 2,sp

ldd #prompt3 ; move cursor to the next line

jsr [printf,PCR] ; “

ldd #inbuf

pshd

ldd #prompt2

jsr [printf,PCR] ; output the number that you entered

leas 2,sp

ldd #prompt3

jsr [printf,PCR] ; move cursor to the next line

swi

prompt1 db “Please enter a number: “,CR,LF,0

prompt2 db “The entered number is: %s “,0

prompt3 db “ “,CR,LF,0

end
When you see the message “Please enter a number:,” enter an integer followed by a carriage
return. The screen output should be similar to what appears here.
>g 1500
Please enter a number:

The entered number is: 1234
User Bkpt Encountered

PP PC SP X Y D = A:B CCR = SXHI NZVC

30 1533 1500 1500 156C 00:03 1001 0000

xx:1533 50 NEGB

>
L4.2 Temperature conversion. Write a subroutine that will convert the temperature in
Fahrenheit to Celsius accurate to one decimal digit. Write a main program that will
1. Prompt the user to enter a temperature in Fahrenheit by displaying the message
“Please enter a temperature in Fahrenheit:” .
2. Call the GetCmdLine() function to read in the temperature.
3. Call a subroutine to convert the input string (representing a decimal number) into a
binary number.
4. Call the temperature conversion subroutine to convert it to Celsius.